High-intensity interval training is not superior to other forms of endurance training during cardiac rehabilitation.

BACKGROUND: High-intensity interval training has recently emerged as superior to continuous endurance training in cardiac rehabilitation upon other training regimes. Individually tailored continuous endurance training and pyramid training could induce comparable effects on peak work capacity as high intensity interval training. DESIGN: A prospective, randomized study. METHODS: Effects of the following isocaloric cycle ergometer protocols on peak work capacity have been assessed in patients with coronary artery disease (n = 60) during 6 weeks of outpatient cardiac rehabilitation, i.e. 18 supervised sessions of exercise training: (1) continuous endurance training (n = 20): 33 min at 65-85% peak heart rate; (2) high intensity interval training (n = 20): 4 × 4 min intervals at 85-95% peak heart rate, each followed by 3 min of active recovery at 60-70% peak heart rate; (3) pyramid training (n = 20): 3 × 8 min of stepwise load increase and subsequent decrease from 65-95-65% peak heart rate, supplemented by 2 min recovery at 60-70% peak heart rate between pyramids. All protocols were preceded by 5 min of warm-up and followed by 5 min cool-down at 60-70% peak heart rate. RESULTS: Attendance during exercise sessions was 99.2%. There were significant increases in peak work capacity of comparable magnitude in all three training groups (begin vs. end: continuous endurance training: 136.0 ± 49.6 W vs. 163.4 ± 60.8 W (21.1 ± 8.5%); high-intensity interval training: 141.0 ± 60.4 W vs. 171.1 ± 69.8 W (22.8 ± 6.6%); pyramid training: 128.7 ± 50.6 W vs. 158.5 ± 57.9 W (24.8 ± 10.8%); within groups all p < 0.001; between groups, p = not significant). CONCLUSION: Endurance training protocols assessed in this study all led to significant increases in peak work capacity of comparable magnitude. Our findings suggest that these protocols can be used interchangeably, which will lead to further individualization of exercise prescription and may therefore result in improved adherence to lifelong behavioural changes.

High incidence of echocardiographic abnormalities of the interatrial septum in patients undergoing ablation for atrial fibrillation.

BACKGROUND: Atrial fibrosis or fatty deposition is known to increase the propensity for the development of atrial fibrillation (AF). Apart from the pulmonic veins, the interatrial septum (IAS) might play a role in the maintenance of AF. In contrast to left atrial anatomy and adjacent veins, the IAS cannot be visualized in detail with computed tomography. Thus, preprocedural transesophageal echocardiography (TEE) may provide important morphologic information beyond exclusion from atrial thrombi. METHODS: The study comprised 108 consecutive patients (mean age 60 ± 11 years; 98 men). AF was paroxysmal in 91 (84%) and persistent in 17 (16%) patients. We investigated the morphological characteristics of the IAS by TEE in patients who underwent radiofrequency ablation of AF. RESULTS: The IAS was structurally abnormal in 46 (43%) patients, showing the following echocardiograhic findings: atrial septal hypermobility or aneurysm (n = 27) associated with a patent foramen ovale (PFO) (n = 11) or with a small atrial septal defect (ASD) (n = 2), a septal flap associated with a PFO or an ASD (n = 8), and an abnormally thickened IAS (n = 12). A thrombus in the left atrial appendage was discovered in only 2 (2%) patients. CONCLUSIONS: A structurally abnormal IAS was diagnosed in nearly half of the patients undergoing ablation therapy for AF. The information obtained by TEE is mandatory to exclude left atrial thrombi prior the ablation procedure. Moreover, detailed knowledge of morphologic characteristics of the IAS facilitates an optimized and safe performance of the transseptal puncture using long sheaths with large diameters.

Comparison between ATS/ERS age- and gender-adjusted criteria and GOLD criteria for the detection of irreversible airway obstruction in chronic heart failure.

BACKGROUND: Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (FEV1/FVC <70%) are extensively used for diagnosis of chronic obstructive lung disease in heart failure (HF). The American Thoracic Society (ATS)/European Respiratory Society (ERS) recommends the use of age- and gender-specific lower limit of normal (LLN) for FEV1/FVC. We compared the impact of these definitions on apparent prevalence of airway obstruction in chronic HF. METHODS: Standardized pre- and post-bronchodilator spirometry was performed in HF patients. Airway obstruction was defined by ATS/ERS criteria as diagnostic standard. Additionally, airway obstruction was calculated using the GOLD criteria. RESULTS: Of the 89 participants who fulfilled the ATS criteria for acceptability and reproducibility, 24.7% met ATS/ERS and 43.8% GOLD criteria for airway obstruction (Chi-square p = 0.007, McNemar <0.001). Sensitivity of GOLD criteria was 100%, specificity 74.6%, positive predictive value 56.4% and negative predictive value 100%. Among all individuals with an FEV1/FVC > LLN, 25.4% were falsely identified when using the GOLD criteria. A majority of false positives qualified for airway obstruction GOLD stage I (FEV1% ≥80%), which was significantly less often observed among true positives (76.5 vs. 31.8%; p < 0.001). Only 31.8% of patients with irreversible airway obstruction detected by the ATS/ERS criteria reported a history of COPD. CONCLUSIONS: In all HF patients with persistent dyspnoea despite optimal HF treatment, spirometric testing should be performed. Application of the GOLD criteria leads to overdiagnosis of irreversible airway obstruction in patients with HF, which may result in inappropriate medical therapy and health-care decisions.

Asymmetric dimethylarginine enhances cardiovascular risk prediction in patients with chronic heart failure.

OBJECTIVE: The purpose of this study was to investigate whether elevated asymmetrical dimethylorginine (ADMA) concentrations are associated with increased cardiovascular risk in chronic heart failure (HF) patients. METHODS AND RESULTS: 253 patients with symptomatic chronic HF and impaired left ventricular function (median age 70 years, 202 males) were followed for a median of 14.2 months (interquartile range 6.8 to 21.2). ADMA and N-terminal pro-brain natriuretic peptide (NT-proBNP) were assessed by high performance liquid chromatography and by an enzyme-linked immunosorbent assay, respectively. Subjects with ADMA concentrations in the highest tertile had a significantly higher adjusted hazard ratio (HR; 2.00; 95% confidence interval [CI] 1.01 to 3.97) for occurrence of an end point (cardiac decompensation, major adverse cardiovascular events or all-cause mortality) compared with patients in the lowest tertile (P=0.046) during the first 6 months of follow-up. NT-proBNP also identified subjects at risk before adjustment for confounders at 6 and 12 months of follow-up. HR for patients with ADMA and NT-proBNP in the highest tertile was significantly increased (3.68, CI 1.67 to 8.14; at 6 months follow-up) compared with patients without ADMA and NT-proBNP in the highest tertile (P<0.001). CONCLUSIONS: Elevated ADMA plasma concentrations are associated with adverse cardiovascular outcome in patients with chronic HF. Quantification of ADMA with NT-proBNP improves risk stratification in this cohort.